[media] v4l: Add camera pan/tilt speed controls

The V4L2_CID_PAN_SPEED and V4L2_CID_TILT_SPEED controls allow to move the
camera by setting its rotation speed around its axis.
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Pawel Osciak <posciak@chromium.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/DocBook/media/v4l/compat.xml

@@ -2545,6 +2545,16 @@ fields changed from _s32 to _u32.
       </orderedlist>
     </section>
 
+    <section>
+      <title>V4L2 in Linux 3.18</title>
+      <orderedlist>
+	<listitem>
+	  <para>Added <constant>V4L2_CID_PAN_SPEED</constant> and
+ <constant>V4L2_CID_TILT_SPEED</constant> camera controls.</para>
+	</listitem>
+      </orderedlist>
+    </section>
+
     <section id="other">
       <title>Relation of V4L2 to other Linux multimedia APIs</title>
 

Documentation/DocBook/media/v4l/controls.xml

@@ -3965,6 +3965,27 @@ by exposure, white balance or focus controls.</entry>
 	  </row>
 	  <row><entry></entry></row>
 
+	  <row>
+	    <entry spanname="id"><constant>V4L2_CID_PAN_SPEED</constant>&nbsp;</entry>
+	    <entry>integer</entry>
+	  </row><row><entry spanname="descr">This control turns the
+camera horizontally at the specific speed. The unit is undefined. A
+positive value moves the camera to the right (clockwise when viewed
+from above), a negative value to the left. A value of zero stops the motion
+if one is in progress and has no effect otherwise.</entry>
+	  </row>
+	  <row><entry></entry></row>
+
+	  <row>
+	    <entry spanname="id"><constant>V4L2_CID_TILT_SPEED</constant>&nbsp;</entry>
+	    <entry>integer</entry>
+	  </row><row><entry spanname="descr">This control turns the
+camera vertically at the specified speed. The unit is undefined. A
+positive value moves the camera up, a negative value down. A value of zero
+stops the motion if one is in progress and has no effect otherwise.</entry>
+	  </row>
+	  <row><entry></entry></row>
+
 	</tbody>
       </tgroup>
     </table>

drivers/media/v4l2-core/v4l2-ctrls.c

@@ -796,6 +796,8 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_AUTO_FOCUS_STOP:		return "Auto Focus, Stop";
 	case V4L2_CID_AUTO_FOCUS_STATUS:	return "Auto Focus, Status";
 	case V4L2_CID_AUTO_FOCUS_RANGE:		return "Auto Focus, Range";
+	case V4L2_CID_PAN_SPEED:		return "Pan, Speed";
+	case V4L2_CID_TILT_SPEED:		return "Tilt, Speed";
 
 	/* FM Radio Modulator controls */
 	/* Keep the order of the 'case's the same as in v4l2-controls.h! */

include/uapi/linux/v4l2-controls.h

@@ -746,6 +746,8 @@ enum v4l2_auto_focus_range {
 	V4L2_AUTO_FOCUS_RANGE_INFINITY		= 3,
 };
 
+#define V4L2_CID_PAN_SPEED			(V4L2_CID_CAMERA_CLASS_BASE+32)
+#define V4L2_CID_TILT_SPEED			(V4L2_CID_CAMERA_CLASS_BASE+33)
 
 /* FM Modulator class control IDs */